CN116529551A

CN116529551A - Conductive refractory brick system

Info

Publication number: CN116529551A
Application number: CN202180072425.1A
Authority: CN
Inventors: C·福斯贝里; D·C·斯塔克
Original assignee: Massachusetts Institute of Technology
Current assignee: Massachusetts Institute of Technology
Priority date: 2020-10-23
Filing date: 2021-08-31
Publication date: 2023-08-01
Also published as: WO2022086630A1; MX2023004577A; US20220132633A1; KR20230078794A; AU2021364476A1; CA3194701A1; JP2023549474A; IL301680A; EP4233102A1; US11877376B2; CL2023001115A1

Abstract

The thermal energy storage system includes a refractory brick lattice structure and an electrode. The refractory brick lattice structure includes one or more conductive refractory brick layers, each conductive refractory brick layer including a plurality of conductive doped metal oxide refractory bricks having one or more airflow vents. The electrode comprises one or more electrode refractory brick layers, each layer comprising a plurality of electrode refractory bricks. The refractory brick lattice structure is heated by applying electrical power to the electrodes. The air flowing through the refractory brick lattice structure may then be heated for use in heat related applications (e.g., industrial applications, commercial applications, residential applications, transportation applications, etc.), some of which may be related to electricity production or other applications related to other purposes requiring heat that may not be related to electricity production.

Description

Conductive refractory brick system

Technical Field

One or more embodiments described herein relate to managing energy storage.

Background

Modern energy generation and distribution networks ("grids") include many different power generation sources. While some generators may operate with a relatively continuous output (e.g., conventional power plants such as coal, oil, natural gas, nuclear, etc.), the power generation capacity of other power sources such as solar or wind energy may vary, for example, based on environmental factors. As more and more solar generators and wind generators are brought online to reduce greenhouse gas emissions, the expansion of the power storage capacity of the grid may take into account the variability of the output power. However, current battery technology has proven unsatisfactory and is very expensive to implement. Attempts have been made to use other types of energy storage systems, such as pumped storage. However, these other systems are site-constrained and not readily available or deployed.

Disclosure of Invention

One or more embodiments described herein provide an improved energy storage system and method that may be used in a variety of applications, including, inter alia, storing power in a power grid.

These and/or other embodiments provide an energy storage system and method that controls the storage of electricity to offset variability in the output of one or more power sources of a power grid, including but not limited to, variability in the output power of solar generators, wind generators, and other power sources that suffer from inconsistent performance due to environmental and/or other factors.

These and/or other embodiments provide an improved energy storage system and method that may be readily deployed in a variety of environments.

These and/or other embodiments provide an improved energy storage system and method that is economical to implement.

According to one or more embodiments, a thermal energy storage system includes a refractory brick lattice structure (checkerwork) including one or more conductive refractory brick layers, each conductive refractory brick layer including a plurality of conductive doped metal oxide refractory bricks having one or more vents to allow airflow through the refractory brick lattice structure; and a first electrode comprising one or more electrode refractory brick layers, each electrode refractory brick layer comprising a plurality of electrode refractory bricks, the first electrode configured to receive electrical power from a source; wherein the refractory brick lattice structure is heated as a result of the application of the received electrical power. With this arrangement, air flowing through the refractory brick lattice structure may be heated by the refractory brick lattice structure to provide heat for various uses, including but not limited to residential heat use, industrial heat use, commercial heat use, transportation use, and/or power production (which may occur in any or all of residential, industrial, commercial, and transportation environments). The concepts described herein may be used in the high temperature heat market and the power market. Thus, after reading the description provided herein, one of ordinary skill in the art will appreciate that the heat storage systems and other embodiments described herein may provide heat to all types of heat users and heat related applications (e.g., industrial applications, commercial applications, residential applications, transportation applications, etc.). It should also be appreciated that some of these applications may involve power production, but other applications may involve other purposes requiring heat that are unrelated to heat production. Thus, while one or more embodiments may be used as an effective replacement for a battery in some cases, other embodiments may be used in a variety of other environments, for example, to provide heat for nearly any purpose.

According to one or more embodiments, an apparatus includes: a first electrode; a second electrode; and conductive refractory bricks, wherein the conductive refractory bricks are disposed in a predetermined pattern between the first electrode and the second electrode, each of the conductive refractory bricks comprising a doped metal oxide material configured to generate heat based on an electrical potential applied between the first electrode and the second electrode.

Drawings

The foregoing and other objects, features and advantages will be apparent from the following more particular description of embodiments, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the embodiments.

FIG. 1 is a block diagram of an illustrative industrial system employing a conductive refractory brick system in accordance with the described embodiments;

FIG. 2A is a graph of material conductivity as a function of temperature for refractory bricks of various materials according to the described embodiments;

FIG. 2B is a graph of electron concentration as a function of temperature for a doped semiconductor refractory brick in accordance with the described embodiments;

FIG. 2C is a series of graphs of electron concentration and resistivity of doped semiconductor refractory bricks as a function of temperature in accordance with the described embodiments;

FIG. 2D is a block diagram of an illustrative electrically heated thermal energy storage (E-TES) system employing electrically conductive refractory bricks in accordance with the described embodiments;

FIG. 3 is a view of an illustrative container system for housing an E-TES system in accordance with the described embodiments;

FIG. 4 is a view of an illustrative E-TES system employing conductive refractory bricks in accordance with the described embodiments;

FIG. 5 is a schematic diagram of an illustrative Y-shaped (wye) configuration electrical connection of electrodes of an E-TES system according to an embodiment described;

FIG. 6 is a schematic diagram of an illustrative Y-shaped configuration electrical connection of electrodes of an E-TES system according to an embodiment described;

FIG. 7A is an image of an illustrative refractory brick system in accordance with the described embodiments;

FIG. 7B is an image of an illustrative refractory brick system in accordance with the described embodiments;

FIG. 8A is a perspective view of an illustrative electrode and conductive refractory brick layout of an E-TES system in a delta configuration in accordance with the described embodiments;

FIG. 8B is a perspective view of an illustrative electrode and conductive refractory brick layout of an E-TES system in a Y-configuration in accordance with the described embodiments;

FIG. 8C is a perspective view of another illustrative electrode and conductive refractory brick layout of an E-TES system in a Y-configuration in accordance with the described embodiments;

FIG. 9 is a block diagram of an illustrative energy distribution and storage grid employing an E-TES system in accordance with the described embodiments;

FIG. 10 is a block diagram of an illustrative concrete kiln system employing an E-TES system in accordance with the described embodiments;

FIG. 11 is a block diagram of an illustrative natural gas power system employing an E-TES system in accordance with the described embodiments;

FIG. 12 is a block diagram of an illustrative nuclear power system employing an E-TES system in accordance with the described embodiments; and

FIG. 13 is a pair of graphs of resistivity as a function of temperature using chromium oxide doped refractory bricks according to the described embodiments.

Detailed Description

One or more embodiments described herein provide systems and methods for performing electrically heated thermal energy storage (E-TES). Such systems and methods may be used for decarbonization for a variety of applications, including but not limited to those related to electrical grids or industrial systems. As more and more renewable energy generators are deployed into the grid, rich and affordable energy storage technologies are desired to cover the cycles in power generation (e.g., solar or wind power generation). The E-TES embodiments described herein may meet these objectives. Moreover, these and/or other embodiments may be used in various industrial processes that generate and/or consume heat, such as furnaces, kilns, refineries, nuclear power plants, and the like. As described herein, some embodiments of E-TES may employ electrically heated refractory bricks to store thermal energy for use as heat or to convert to electricity.

FIG. 1 shows an embodiment of an illustrative deployment of an E-TES system employing heated refractory bricks in a power grid or industrial system. As shown in FIG. 1, heated refractory brick E-TES system 108 may receive power input 104 to heat the refractory brick, and may also receive air input 102. For example, the air input 102 may be "cool" air, ambient temperature air, exhaust from an industrial process, and the like. The input air is heated by the heated refractory bricks 108 and may be output as hot air 110. In some embodiments, the temperature of the output hot air 110 may be adjusted by a temperature adjustment 114, which temperature adjustment 114 may include air provided by the air bypass 106 from the input air 102. For example, if the temperature of the heated refractory bricks 108 is greater than the desired temperature of the output hot air 110 provided to the output user 112, the temperature of the output air may be adjusted by providing cooler air (e.g., via the bypass 106), and the output user 112 may be, for example, a kiln or furnace. Alternatively, if the temperature of the heated refractory bricks 108 is less than the desired temperature of the output air 110, additional fuel (e.g., natural gas) may be provided via the temperature adjustment 114 to increase the temperature of the output hot air 110.

In some embodiments, the output user 112 may be a natural gas power cycle plant. According to one or more embodiments, a predetermined efficiency, e.g., a round trip electrical efficiency of 55-60%, may be achieved. In other embodiments, the output user 112 may be a nuclear power plant (e.g., a generation IV nuclear reactor), and the E-TES system may achieve, for example, 65-70% round trip electrical efficiency. In one embodiment, an E-TES system (e.g., refractory bricks 108) may be juxtaposed adjacent to user 112.

However, existing systems do not achieve a sufficiently high temperature range and/or suffer from significantly reduced life due to the high temperatures required. For example, existing heaters provide a limited temperature range (e.g., a T peak of the heater < a T peak of the refractory brick), a limited charge rate (e.g., a limited ability to transfer heat from the heater to the refractory brick due to surface wattage loading of the heater and/or temperature gradients and thermal stresses of the refractory brick), and a significantly shortened heater life due to high temperatures, which may result in high replacement costs.

Thus, one or more embodiments provide direct resistive heating of the refractory bricks 108. For example, one or more embodiments may electrically heat the insulating blocks of refractory bricks to very high temperatures (e.g., 1000 ℃ to 2000 ℃ although higher temperature ranges are possible). The heat stored in the refractory bricks 108 may be delivered as output air 110 by blowing air through channels in the hot refractory bricks to deliver the stored heat for industrial heat applications (e.g., kiln, furnace, refinery) or power generation applications (e.g., power plant).

The Direct Resistance Heating (DRH) of the refractory brick 108 eliminates the drawbacks of available heaters and the temperature is limited only by the nature of the refractory brick, enabling higher temperature applications, increased energy density, and higher charge rates. In addition, the refractory brick system eliminates the wattage load limitation of existing heaters and designing the refractory bricks to provide near uniform heat generation throughout the refractory brick system reduces stress on the system, which in turn reduces maintenance costs and provides more reliable operation. Thus, according to one or more embodiments, a conductive brick is provided that can be mass produced to form a stable stackable circuit for joule heating that can be cycled throughout a predetermined range (e.g., about 1000 ℃ to about 1800 ℃, or another range) for an extended period of time (e.g., years) per day.

The described embodiments provide refractory bricks made of a suitable material having electrical conductivity to provide the desired heating characteristics. The gradual resistivity-temperature trend dominated by carrier mobility may be a property of refractory bricks.

Fig. 2A shows a graph providing an example of the conductivity of different materials as a function of temperature. The conductivity of a material can be determined, for example, by equation (1):

σ＝q*μ _c (T)N _c (T) (1)

Wherein T is temperature, q is charge of carrier, μ _c Is carrier mobility, and N _c Is the carrier number density.

The carrier mobility μ can be estimated based on equation (2) _c ：

μ _c (T)∝T ^-3/2 Or (b)Wherein E is _h Is the free charge "jump" energy and k is the boltzmann constant. Jump energy involves the extra energy of the free charge moving in some lattices, and E _h Depending on the materialType (metal zero). T (T) ^-3/2 The term represents the slowed mobility due to the interaction of the larger carriers with lattice vibrations. In some cases, the "jump" term may dominate and produce a sharp increase in mobility at relatively low temperatures. At most relevant temperatures (e.g., temperatures within a predetermined range), the "jump" term tends to plateau and shrink by T ^-3/2 The term becomes the dominant behavior. Mobility mu _c (T) may have a tendency to decrease or increase with temperature and may be the standard in most heating devices. Here, carrier density N _c The index and temperature dependence of (T) vary based on the material, and lattice vibration can generally increase with temperature, which reduces carrier mobility.

As shown in fig. 2A, in metals, electrons have a continuous allowable energy (e.g., N _c Constant) such that the heating is generally stable and any uneven heating is corrected by decreasing the conductivity in the hotter areas, and the colder areas have higher currents than the warmer areas. Therefore, the conductivity can be estimated as σ+_T ^-3/2 。

In semiconductor refractory bricks, the semiconductor intrinsic conductivity has a band gap between the conduction and valence bands such that electrons are localized and cannot jump energy levels without thermal activation. Thus, the intrinsic conductivity can be estimated asWhere Eg is the semiconductor bandgap energy.

In the case of semiconductor extrinsic conductivity, electron donor or acceptor sites may be formed when the semiconductor is doped with one or less valuable electrons than the element being replaced. The activation energy Ea associated with "donating" or "accepting" electrons may be less than the semiconductor bandgap energy Eg. Thus, the intrinsic conductivity can be estimated asThe exponential conductivity trend of semiconductors results in thermal sites receiving even more electricityFlow, which may lead to a short circuit condition in the rest of the refractory brick stack.

Thus, according to one or more embodiments, a "metallic" behavior may be achieved in a high temperature ceramic in a highly oxidizing environment. Doping the semiconductor material to achieve a "depletion" period prior to the exponential trend takeover allows three distinct conductivity regions to be formed: intrinsic, extrinsic (or "depletion") and ionized (or "frozen"), such as shown in the graph of fig. 2B. As shown in fig. 2B, nc (T) is constant in the extrinsic region, and thus exhibits metal-like properties. As shown in FIG. 2C, in the unstable region, extrinsic carriers are activated Wherein carrier activation tends to plateau as all carriers are activated, resulting in reduced mobility and more metal-like behavior, wherein conductivity is constant with temperature (e.g., σ ^-3/2 ). As the temperature continues to rise, the intrinsic carriers become activated, eventually exceeding the extrinsic carriers, and entering the unstable region

Fig. 2B and 2C illustrate examples of desired operating temperature ranges (e.g., depletion regions) where the conductivity of the refractory brick material may be set to be substantially constant by modifying the material and dopant levels to select an upper temperature limit TU and a lower temperature limit TL. The temperatures TU and TL depend on the semiconductor bandgap energy Eg, which is the bandgap energy (eV) inherent to the refractory block material, ea, which is the activation energy (eV) of the dopant sites through interaction between the dopant material and the block material, and Na, which is the density (per cm) of the added dopant material ³ )). Typically, the depletion region shifts to higher temperatures as doping increases.

Fig. 2C shows a doped SiC ceramic heater, also a common refractory brick material, with TL of about 800 ℃ and TU of about 1600 ℃. Doped SiC is generally unsuitable for E-TES due to oxidation, which prevents current flow between refractory bricks and ultimately destroys the bulk properties of the material.

Thus, in accordance with one or more embodiments, a metal oxide (e.g., chromium oxide (Cr ₂ O ₃ ) A refractory brick block material). Na may be doped using a dopant material having a relatively low Ea to achieve the desired temperature range TL to TU. The goals of the selection are to achieve low TL (-700 ℃ or less), high TU (-1800 ℃ or more), a large temperature range (e.g., depletion range (-1000 ℃ or more), and high Na (e.g., heavy doping) so that impurities (-1020/cm) can be ignored ³ Or higher).

FIG. 2D illustrates an example of a stable, stackable semiconductor refractory brick that may implement metal conductivity behavior for an electrically heated thermal energy storage (E-TES) system may be provided in accordance with one or more embodiments. As shown in FIG. 2D, E-TES system 200 may include a "top" electrode 202 and a "bottom" electrode 204. Between the electrodes 202 and 204 is a layer of refractory bricks, shown as layer of refractory bricks 206. The refractory brick layer 206 includes a plurality of stackable refractory bricks 208, which plurality of stackable refractory bricks 208 may be located, for example, in overlapping relationship with each other at different levels. In another embodiment, the refractory bricks 208 may all be on the same horizontal plane. A plurality of stackable refractory bricks 208 may form air channels 210 between adjacent pairs of each refractory brick because the refractory bricks 208 are free to stack (which also allows for thermal expansion of the refractory bricks). Generally, the air flow may be in at least one predetermined direction. An example of a direction is indicated by dashed line 212.

FIG. 3 shows a view of an illustrative regenerator vessel that may be used to house a refractory brick E-TES system such as that shown in FIG. 2D. As shown in fig. 3, the container system 300 may include an air inlet 310, a lower plenum 308, a body 312, an upper plenum 304, and a hot air outlet 302. Together, the plenums 304 and 308 and the body 312 may form a container 314. In general, the vessel 314 may be an insulated steel vessel juxtaposed at an industrial facility or power plant. In some embodiments with higher air pressure, the vessel 314 may be prestressed concrete. As shown, the vessel 314 may house a predetermined pattern (e.g., a lattice structure) of refractory bricks, shown generally as refractory bricks 306, and which may be implemented such as described with respect to fig. 2D.

As shown, the lower plenum 308 is a hemispherical inlet of the air flow into the vessel 314 and the upper plenum 304 is a hemispherical outlet of the air flow through the vessel 314. The air flow is provided from the inlet 310 and flows through the refractory bricks 306, as indicated by the dashed arrows 316, and then exits through the hot air outlet 302. In some embodiments, the lower plenum 308 includes a support structure (e.g., corrosion resistant steel, ceramic arches, or dome structures, etc.) for the vessel 314 to support the vessel 314 as a standing structure. Additionally, in some embodiments, the lower plenum 308 may be maintained at a lower temperature than the remainder of the vessel 314 by employing an insulating layer between the lower plenum 308 and the refractory brick lattice structure 306, and/or by employing one or both of passive and active cooling. Although shown as being generally cylindrical in fig. 3, the container 314 has a particular size and shape that varies based on its use and application.

As will be described, the vessel 314 may have a large power input (e.g., as three-phase AC power or as DC power), and in one embodiment, the refractory brick lattice structure 306 may be implemented as three isolated conductive refractory brick sections having a predetermined configuration. Examples include a triangle configuration, a Y-shaped configuration, or another configuration. In one embodiment, the three-phase power may be provided by an electrical penetration to a refractory brick lattice structure and/or conductive electrode that withstand a high temperature oxidizing environment.

Fig. 4 illustrates an embodiment of a refractory brick lattice structure 306 that may be included in the regenerator vessel of fig. 3. As shown in FIG. 4, the refractory brick lattice structure 306 may include a plurality of layers or portions of chimney lattice (chemical) refractory bricks having different conductivities and/or functions.

As shown in fig. 4, the illustrative embodiment may employ three general types of refractory bricks: insulating refractory bricks 402, 410, 412, and 414, electrode refractory bricks 404 and 408, and conductive refractory bricks 406. The insulating refractory bricks are electrically insulating and may be implemented using a predetermined combination of materials. An example combination isAlumina (alumina)/magnesia (silica). The electrode refractory brick is highly doped (-10) ²¹ /cm ³ ) Is highly conductive and provides low heat generation (e.g., electrode refractory bricks do not require a small resistance-temperature coefficient). The conductive refractory brick is carefully mixed and doped (-10) ²⁰ /cm ³ ) Is about 10 times more resistive than the electrode refractory bricks and has a small resistance-temperature coefficient.

As shown in fig. 4, the top layer, shown as top insulating layer 402, of insulating refractory brick electrically insulates top electrode 404 from the structure of vessel 314 and provides thermal mass and weight for good electrical contact between top electrode 404 and conductive refractory brick lattice structure 406. In some embodiments, top electrode 404 may be made of a plurality of electrode refractory brick portions, shown as electrode portions 404a-n. In some embodiments, there may be three electrode portions of top electrode 404, for example, to isolate the individual phases of a three-phase power input. Each of the electrode portions 404a-n may be separated by one or more insulating refractory brick portions (shown as insulating portion 414). In another embodiment a different number of parts may be included.

The conductive refractory brick lattice structure 406 may also include a plurality of conductive refractory brick sections, shown as conductive sections 406a-n, which in some embodiments may be generally aligned with and correspond to the electrode sections 404a-n for three-phase power. The conductive refractory brick lattice structure 406 is the site for heat generation and storage in the E-TES system. The bottom electrode 408 is also made of electrode refractory bricks. In embodiments employing a wye configuration of three-phase power, bottom electrode 408 is a single piece forming a neutral point contact for the three-phase wye configuration, as shown in fig. 4. In embodiments employing a delta configuration of three-phase power, the bottom electrode 408 may be divided into a plurality of conductive portions to transfer power through the lattice structure 406 to provide an impedance load between the phases. The bottom insulating layer 410 is made of insulating refractory bricks and electrically and thermally insulates the bottom electrode 408 from the vessel 314. In another embodiment a different number of conductive portions may be included.

FIG. 5 illustrates an embodiment of an E-TES system 500 employing a Y-configuration three-phase power, for example, by introducing power only at top electrode 404 to allow the container penetration of the electrode to be located at the top of container 314. As shown, the line source 502 generates three phases of power and a single phase is provided to a corresponding one of the top electrode portions 404 a-c. As shown in FIG. 5, each electrode portion 404a-c may have one or more electrical penetrations of the container 314, shown as electrical connections 504. The illustrative embodiment shown in fig. 5 may include electrical connections 504 only at the top of the container 314. For example, in embodiments having an electrical connection at the top electrode 404 only at the top of the container 314, components may be more easily maintained or replaced by removing only the top insulating layer 402. Other embodiments may additionally or alternatively employ a connection at the bottom of vessel 314, which may be more difficult to access for maintenance, but may benefit from cooler temperatures due to air flow through the E-TES system. In some embodiments, the electro-penetration 504 may be temperature and/or pressure controlled, for example, by an annular vessel sleeve, to maintain a reliable ceramic/metal interface between the electro-penetration 504 and the electrode refractory brick portion 406.

FIG. 6 shows an illustrative electrical schematic of an embodiment of a Y-shaped configuration of E-TES system 500. In this embodiment, each portion of the top electrode 404 corresponds to a given phase provided from the power generator 502, and the bottom electrode 408 may be used to provide a neutral point, optionally with a neutral connection 602.

As described herein, embodiments provide conductive refractory bricks made from doped metal oxides. Doped metal oxide refractory bricks provide a high temperature operating range (-1800 ℃) and are electrically conductive, electrically stable (exhibiting near constant resistivity above 400 ℃), thermally cycled over many cycles, physically stackable and have low contact resistance (about 0.1 omega-cm at 5 PSI) ² ) And is inexpensive.

Fig. 7A shows an illustrative embodiment of a refractory brick lattice structure 700. The lattice structure 700 may include multiple layers (or tiers) of refractory bricks 702, shown as layers 710a-n, stacked on top of each other. As shown, each refractory brick 702 may be implemented as a chimney brick having one or more chimney vents 708 passing through the refractory brick along an axis of the refractory brick (e.g., vertically from bottom to top). For example, as shown, each refractory brick 702 includes seven chimney vents 708, each chimney vent 708 having a generally hexagonal cross-sectional shape. The overall shape of each refractory brick 702 is selected to be generally symmetrical to allow for easy stacking and placement within a lattice structure comprising a plurality of refractory bricks, and also to allow for easy fabrication. For example, as shown in FIG. 7, the refractory brick 702 may also be generally hexagonal and may include one or more ridges 706 and/or teeth 704 around the outer edge or periphery of the refractory brick. The external ridges and teeth may facilitate the placement of multiple refractory bricks in a lattice structure and facilitate interlocking between refractory bricks. Furthermore, the shape of the refractory bricks 702 and the ridges 706 and teeth 704 may facilitate deployment of the refractory bricks 702 in differently shaped containers (e.g., the container 314 of FIG. 3) without changing the refractory bricks. Similarly, one side (e.g., top) of each refractory brick 702 may include a recess 712, and the other side (e.g., bottom) may have a corresponding protrusion (not shown) to fit within the recess, thereby further facilitating stacking and interlocking of refractory bricks.

FIG. 7B shows another illustrative embodiment of a refractory brick lattice structure, shown as refractory brick lattice structure 720. As shown, each refractory brick 722 may include one or more chimney vents 728. As shown, each chimney vent may be generally square in cross-section, and each chimney vent passes through the refractory brick along an axis of the refractory brick (e.g., vertically from bottom to top). The edges of each refractory brick 722 may be beveled or rounded to facilitate placement within a lattice structure and/or deployment within differently shaped containers, as indicated by edges 724 and 726. Some embodiments may include one or more side notches 730 to facilitate interlocking between refractory bricks.

The refractory brick embodiments shown in fig. 7A and 7B may allow the bricks to expand and contract with temperature changes, without requiring any material between the bricks that may be damaged by expansion and contraction and/or extreme temperatures, and the deformability allows the conductive refractory bricks to maintain a good electrical connection as the material deforms with temperature changes.

Thus, the refractory brick is prepared by mixing a bulk material in powder form (e.g., chromium oxide) with a desired amount of a dopant material (e.g., nickel oxide). In some embodiments, the dopant material may be between about 2% and 5% of the mixture. The mixture is then mechanically pressed into a brick having a desired size, shape, and form factor and including one or more chimney vents to allow airflow through the refractory brick. The refractory bricks are then sintered to bricks at temperature/pressure.

In the described embodiments, the refractory bricks may be nickel doped chromia, magnesium doped chromia, lithium doped nickel oxide, copper doped nickel oxide, aluminum doped zinc oxide, cerium doped stabilized zirconia, niobium doped titania, or other high temperature metal oxides doped with metals of different valence states, which may also be mixed with electrically inert oxides such as alumina, magnesia, or silica. For example, in some embodiments, some alumina (e.g., aluminum oxide) may be mixed with nickel-doped chromium oxide (e.g., chromium oxide), which may make the refractory brick cheaper and/or stronger without significantly changing the electrical properties of the refractory brick.

FIG. 8A shows an illustrative example of a refractory brick system 800, which may be an implementation of the system shown in FIG. 4. As shown, the top electrode 802 may include one or more insulating portions 822 such that the insulating portions 822 divide the top electrode 802 into a plurality of conductive portions 820. Similarly, the refractory brick lattice structure portion 804 can also include one or more insulating portions 818 such that the insulating portions 818 divide the refractory brick lattice structure 804 into a plurality of conductive portions 816. The bottom electrode 806 may also include one or more insulating portions 812 such that the insulating portions 812 divide the bottom electrode 806 into a plurality of conductive portions 810. As described herein, each of the top electrode 802, the bottom electrode 806, and the refractory brick lattice structure 804 may include multiple layers of refractory bricks, with the insulating and conductive portions of each layer overlapping and generally aligned with each other such that the multiple layers form a multi-layer whole. Thus, each of the top electrode 802, bottom electrode 806, and refractory brick lattice 804 may have a plurality of multi-refractory brick layer electrically isolated portions.

In some embodiments, the geometry of the conductive portions 820, 816, and 810 may be arranged such that the conductive portions overlap one another, thereby forming an electrical connection and forming a path for conducting electricity through the refractory brick system 800. For example, as shown in fig. 8A, line 808 indicates an illustrative circuit path of system 800 that overlaps based on the arrangement of conductive portions 820, 816, and 810.

Accordingly, one or more embodiments provide conductive refractory bricks that can form an air stable and stackable conductive medium, and the manner in which the refractory bricks are stacked can form a desired current path through the entire system 800. As described herein, the refractory brick lattice 804 is the site of heat generation. In general, the refractory brick lattice 804 and top electrode 802 may be divided into a plurality (e.g., three) of electrically isolated phase sections to receive each phase of three-phase power. In addition, each phase section may be further partitioned to form a "serpentine" electrical path 808 to achieve desired system resistance and charging behavior and to ensure passive charging stability of the system 800. For convenience, line 808 indicates electrical paths for a single electrical phase of system 800, and electrical paths for other phases may have similar configurations.

As shown, the conductive refractory bricks are separated by insulating refractory bricks to form a serpentine electrical path indicated by line 808 through the top electrode 802, refractory brick lattice 804 and bottom electrode 806. The top electrode 802 and the bottom electrode 806 are divided by insulating refractory bricks in a different pattern than the refractory brick lattice structure 804, but the patterns may overlap each other to connect the vertical electrical paths, as shown by lines 808.

In some embodiments, both the "start" and "end" of electrical path 808 are at top electrode 802, thereby avoiding having to provide any electrical penetrations at the bottom of the container, e.g., as described with respect to fig. 5. However, other embodiments may alternatively or additionally employ an electro-penetration at the bottom of the container, as described herein. For example, if it is desired to have the power connection at the bottom of the container instead of the top, the lattice pattern of the illustrative embodiments described herein may be reversed (e.g., as shown in fig. 8A, 8B, and 8C).

As shown in fig. 8A, the electrical system operates in a delta configuration. The number of serpentine paths desired in the system (such that the electrical penetrators are on top of the system) will determine the operating configuration. The system has a triangular configuration when the number of serpentine paths is even and a Y-shaped configuration when the number of serpentine paths is odd. Fig. 8A shows an illustrative "six channel triangle configuration" system. Further, although generally described herein as employing three-phase AC power, some embodiments may employ DC power, for example, when powered by a DC power source such as a solar panel array or a rectifier. As described above, the electrical path 808 is a single-phase serpentine electrical path for a three-phase system, and thus a three-phase system will take three separate electrical paths. In a DC system, the same serpentine configuration of electrical paths 808 used in a delta configuration may be used, but instead the three electrical paths of a three-phase system are connected in series between two nodes of the DC power supply.

According to one or more embodiments, the width of insulating portions 822, 818, and 812 is a minimum of two refractory bricks to maintain isolation in a staggered pattern, although other embodiments may include wider insulating portions. As shown in fig. 8A, the conductive region 816 of the refractory brick lattice 804 is sized small enough (in some embodiments, the cross-section is in the range of 0.25m to 1.5 m) so that conduction and heat are conducted fast enough to avoid runaway conditions, and this results in uniformity of temperature throughout the refractory brick lattice 804. In some embodiments, the dimensions of the various conductive regions 816 are substantially similar such that the current flow between the regions is symmetrical, resulting in a more uniform temperature distribution throughout the refractory brick lattice 804. In some embodiments, the height of the refractory brick lattice structure 804 (e.g., the conductive region 816 and the insulating portion 818) is in the range of tens of meters (e.g., typically 20-40 m).

FIGS. 8B and 8C show illustrative embodiments of electrode and conductive refractory brick layouts for a Y-configured E-TES system. For example, FIG. 8B shows an illustrative refractory brick system 801 employing an electrical path 808 in a "three channel" Y-shaped configuration. Similar to fig. 8A, electrical path 808 represents one of the electrical paths in a three-phase system. As described herein, in some embodiments, a given electrical path 808 corresponds to one of the phase legs of a three-phase system and may begin in a given one of the conductive regions 820 of the top electrode 802. Each electrical path 808 may end at a Y-node 821 and current through the path 808 for one of the legs of the three-phase system flows back radially through the circuits for the other legs of the three-phase system.

Although fig. 8B shows each serpentine path 808 as having the same (or substantially similar) shape, this is not required by the system. In one or more embodiments, electrical paths 808 having the same (or substantially similar) flow areas may be employed to avoid current bottlenecks that may occur in the event of overheating. As shown in fig. 8A and 8B, each layer 802, 804, and 806 of the refractory brick system may have a predetermined geometry (e.g., may be generally hexagonal), for example, to facilitate assembly within a vessel having a generally circular cross-sectional shape, although other shapes and configurations are possible.

FIG. 8C shows an illustrative refractory brick system 803 employing layers 802, 804, and 806 having a substantially square or rectangular cross-sectional shape, which may be advantageously used in vessels of the same cross-sectional shape. As shown in fig. 8C, the electrical path 808 is in a "three-channel" Y-shaped configuration. Similar to fig. 8A, electrical path 808 represents one of the electrical paths in a three-phase system. As described herein, in some embodiments, a given electrical path 808 corresponds to one of the phase legs of a three-phase system and may begin in a given one of the conductive regions 820 of the top electrode 802. Each electrical path 808 may end at a Y-node 821 and current through the path 808 for one of the legs of the three-phase system flows back radially through the circuits for the other legs of the three-phase system. Although shown in fig. 8C as each serpentine path 808 having the same (or substantially similar) shape, this is not required by the system. Preferably, the described embodiments will employ electrical paths 808 having the same (or substantially similar) surface area (not necessarily shape) such that the current is substantially the same in each path, thereby avoiding the higher resistance current bottleneck where overheating may occur.

Thus, the E-TES refractory brick system described in accordance with one or more embodiments may implement heating systems of different sizes, shapes, and temperatures (up to a limit, e.g., -2000 ℃ or another limit in air). The refractory brick system may have a modular design in terms of shape and size and thus may be adapted to a variety of furnace or vessel shapes and sizes. Furthermore, the refractory brick system as described herein may be compatible with standard control systems while achieving a hotter temperature than other systems may achieve while operating with high stability over a longer heater life than other solutions.

FIG. 9 shows an illustrative embodiment of an E-TES refractory brick system 912 within an example power distribution grid 900. As shown in FIG. 9, E-TES system 912 may be used in conjunction with existing power generation and storage technologies (e.g., power generator 902, thermal generator 904, synthetic fuel system 906, power circulation system 908, and conventional electrical storage system 910) to store excess power as heat and provide the stored energy as power to power consumer 914 or as heat to heat consumer 916.

FIG. 10 illustrates an embodiment of an E-TES refractory brick system as described herein employed, for example, in one or more cement kilns. As shown, the E-TES system may receive cooler air from a grate cooler (grate cooler) of a cement plant and then supply electrically heated air to one or both of a rotary kiln and/or a precalciner (precalciner). This may lead to a significant reduction of carbon emissions from the cement plant and may also lead to substantial energy cost savings (renewable energy surplus). Reducing the use of combustion gases may result in easier calcination of the cement. Finally, the E-TES system was estimated to be very cost effective for the cement plant, estimated to be about 5% of the total cost of the cement plant.

FIG. 11 illustrates an embodiment of an E-TES system that may be used to act as a battery when coupled to a power plant, which may be, for example, a natural gas power plant, shown as power plant 1100. As shown, air may be provided from compressor 1104 to E-TES system 1106. E-TES system 1106 is electrically heated to provide hot air to turbine 1108, which in turn is provided to heat recovery steam generator 1110 and stack 1112. The turbine provides power to the compressor 1104 and the generator 1102. In one embodiment, natural gas may be injected to increase heat to even higher levels. The system may achieve a predetermined efficiency, e.g., a round trip energy efficiency of 55-65% or a different efficiency range.

FIG. 12 illustrates an embodiment of an E-TES system that may be used with an air circulation system, for example, in a nuclear power plant or a solar power plant. As shown, power plant system 1200 may include an E-TES system 1206, where E-TES system 1206 receives cold air from one or more salt-air heaters 1204 and provides heated air to turbine 1202, and turbine 1202 may in turn drive a generator 1208 and/or a heat recovery steam generator 1212. Zero carbon fuel may be added to the output of E-TES system 1206 to raise or otherwise adjust the temperature to a desired range prior to input to the turbine. In one example embodiment, the E-TES system may achieve round trip electrical efficiency of 65-70% or greater, but may achieve different levels of efficiency.

Fig. 13 shows a first graph 1300 illustrating an example of the resistance of a doped chromia refractory brick as a function of temperature. Graph 1302 shows an enlarged view of the area of graph 1300 indicated by square 1304. As shown, the doped chromia refractory brick achieved very low resistivity (< 0.5 Ω -cm), which was almost linear between 900 ℃ and 1500 ℃.

Thus, in accordance with one or more embodiments, an E-TES system is provided that may be used in industrial and/or combined cycle plant applications operating at medium to high temperatures. These may be, for example, those using moderate temperature heat (e.g., <500 ℃) such as steam systems, chemical plants, paper mills, etc., and may also be those useful for high temperature applications (e.g., -800-2000 ℃) such as steel, aluminum, cement, glass, and other high temperature industrial processes.

After reading the description provided herein, it should therefore be appreciated that the heat storage systems and other embodiments described herein may provide heat to all types of heat users and heat related applications (e.g., industrial applications, commercial applications, residential applications, transportation applications, etc.). Some of these applications may involve power production, but other applications may involve other purposes requiring heat that are unrelated to heat production. Thus, while one or more embodiments may be used as an effective replacement for a battery in some cases, other embodiments may be used in a variety of other environments, for example, to provide heat for nearly any purpose.

As used herein, the term "metal oxide" generally refers to any polymer, molecule, or solid that contains metal or metalloid cations and oxide anions. These include, but are not limited to, transition metal oxides, rare earth metal oxides, alkali metal oxides, and alkaline earth metal oxides. The structure includes, but is not limited to, binary monoxide MO, dioxide MO ₂ Sesquioxide M ₂ O ₃ Cuprite oxide M ₂ O, and multimetal oxides including, but not limited to spinel structure MN ₂ O ₄ And perovskite MNO ₃ Wherein M and N are different metallic species.

Reference herein to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the claimed subject matter. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments necessarily mutually exclusive of other embodiments. The same applies to the term "embodiment".

To the extent that directional terms (e.g., upper, lower, top, bottom, parallel, vertical, etc.) are used in the specification and the claims, such terms are merely intended to aid in describing various embodiments and are not intended to limit the claims in any way. These terms are not required to be precise (e.g., precisely perpendicular or precisely parallel, etc.), but are intended to apply to normal tolerances and ranges. Similarly, unless expressly stated otherwise, each numerical value and range should be construed as being approximate, as if the word "about", "substantially" or "approximately" preceded the value of that value or range.

Also for purposes of this specification, the terms "coupled", "connected", "connecting" or "connected" refer to any manner in which energy is transferred between two or more elements.

It should be understood that the steps of the illustrative methods set forth herein do not necessarily have to be performed in the order described. Likewise, additional steps may be included in these methods, and certain steps may be omitted or combined in methods consistent with various embodiments.

It will be further understood that various changes in the details, materials and arrangements of parts which have been described and illustrated in order to explain the nature of the described embodiments may be made by those skilled in the art without departing from the scope of the appended claims.

Claims

1. A thermal energy storage system comprising:

a refractory brick lattice structure comprising one or more conductive refractory brick layers, each conductive refractory brick layer comprising a plurality of conductively doped metal oxide refractory bricks having one or more vents to allow gas flow through the refractory brick lattice structure; and

A first electrode comprising one or more electrode refractory brick layers, each electrode refractory brick layer comprising a plurality of electrode refractory bricks, the first electrode configured to receive electrical power from a source;

wherein the refractory brick lattice structure is heated as a result of the application of the received electrical power, and wherein air flowing through the refractory brick lattice structure is heated by the refractory brick lattice structure.

2. The system of claim 1, further comprising:

a second electrode comprising one or more electrode refractory brick layers, each electrode refractory brick layer comprising a plurality of electrode refractory bricks;

wherein the refractory brick lattice structure comprises a plurality of electrically isolated lattice structure sections and the first electrode comprises a plurality of electrically isolated electrode sections; and is also provided with

Wherein the second electrode is configured to electrically couple two or more of the electrically isolated lattice structure portions of the refractory brick lattice structure to form an electrical transmission path through the refractory brick lattice structure.

3. The system of claim 2, wherein each of the plurality of electrically isolated electrode portions is configured to receive an isolated electrical phase from the source.

4. The system of claim 2, wherein the second electrode is configured to provide a neutral point of electrical power provided as three-phase electrical power, and wherein the thermal energy storage system operates in a Y-configuration.

5. The system of claim 1, further comprising one or more insulating layers comprising one or more insulating refractory brick layers, each insulating refractory brick layer comprising a plurality of non-conductive refractory bricks having one or more vents for allowing airflow through the refractory bricks.

6. The system of claim 1, wherein the electrically conductive doped metal oxide refractory brick comprises one of: chromium oxide doped with nickel, chromium oxide doped with magnesium, nickel oxide doped with lithium, nickel oxide doped with copper, zinc oxide doped with aluminum, stabilized zirconium oxide doped with cerium, and titanium oxide doped with niobium.

7. The system of claim 6, wherein the doping concentration of the electrically conductive doped metal oxide refractory brick is about 10 ²⁰ /cm ³ 。

8. The system of claim 1, wherein the electrode refractory brick comprises one of: chromium oxide doped with nickel, chromium oxide doped with magnesium, nickel oxide doped with lithium, nickel oxide doped with copper, zinc oxide doped with aluminum, stabilized zirconium oxide doped with cerium, or titanium oxide doped with niobium.

9. The system of claim 8, wherein the electrode refractory bricks are at about 10 ²¹ /cm ³ Is highly doped to have high conductivity and provide low heat generation.

10. The system of claim 5, wherein the non-conductive refractory brick comprises one or more of alumina, magnesia, or silica.

11. The system of claim 1, wherein the refractory brick lattice is heated to a temperature between 1000 ℃ and 2000 ℃.

12. The system of claim 2, wherein:

the second electrode includes a plurality of electrically isolated second electrode portions, an

The plurality of electrically isolated lattice structure portions, the plurality of electrically isolated electrode portions, and the plurality of electrically isolated second electrode portions are configured to provide an electrical path through each electrically isolated lattice structure portion.

13. The system of claim 12, wherein the number of serpentines per electrical path is even for the thermal energy storage system to operate in a three-phase delta configuration, and wherein the number of serpentines per electrical path is odd for the thermal energy storage system to operate in a three-phase wye configuration.

14. The system of claim 8, wherein the dopant mixture is about 2% to 5%.

15. The system of claim 1, wherein the electrically conductive doped metal oxide refractory brick comprises a high temperature metal oxide doped with metals of different valence states.

16. The system of claim 15, wherein the electrically conductive doped metal oxide refractory brick further comprises an electrically inert oxide.

17. The system of claim 16, wherein the electrically inert oxide comprises one of alumina, magnesia, or silica.

18. An apparatus, comprising:

a first electrode;

a second electrode; and

the conductive refractory brick is made of a conductive material,

wherein the conductive refractory bricks are disposed in a predetermined pattern between the first electrode and the second electrode, each of the conductive refractory bricks comprising a doped metal oxide material configured to generate heat based on an electrical potential applied between the first electrode and the second electrode.

19. The apparatus of claim 18, wherein:

the predetermined pattern comprises a plurality of overlapping layers of the conductive refractory bricks, an

The conductive refractory bricks are spaced apart to form an air flow channel.

20. The apparatus of claim 18, wherein each of the conductive refractory bricks comprises a dopant concentration corresponding to a temperature of the heat generated based on the electrical potential applied between the first electrode and the second electrode.